A context menu displays a list of actions applicable to the current context.
It is normally hidden from view (except menu bars) and drops
down when the user right-clicks on something.

Context menus should be considered accelerators for advanced desktop users.
Many mouse users don’t think to right-click on things. The right-click gesture
required to show a context menus can be difficult to perform on many laptops,
and it is flat-out impossible on a touch device.

Provide a context menu for any item with actions that can be performed on it.

Provide a context menu for common actions like ‘Copy’ and ‘Paste’ for
textual controls, or navigation actions like ‘Forward’ and ‘Backward.

Do not use context menus as the only way to access functionality. Every item
in a context menu must be available via a method that is somehow visible by
default–typically the app’s main menu bar, but also
via toolbar buttons.